Sound-reproducing apparatus.



F.CHENEY.

SOUND REPRODUCING APPARATUS.

f APPLICATION FILED sEPT.22, I9I3.

1,170,803. Patented Feb. 8, 1916.

v UNITEE sTATEs PATENT GFFICE.

FOREST CHENEY, OECHICACO, ILLINOIS, AssICNOH, BY IvIEsNE AssICNlvIEN'rs,l To CHENEYTALKING MACHINE COMPANY, or CHICAGO, ILLINOIS, A CORPORATION or ILLINOIS; Y

sOUNn-nErnonucINe APPAaATUs.

i Y. Specification of Letters Patent. k Patentd Feb, S, 1916 Application filed September 22, 1913. Serial No.l 791,237.

To all whom t may concern Y Be it known that I, FOREST CHENEY, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Sound-Reproducing Apparatus, of which the following is a specification. Y

The principal object of my invention is to provide a new and improved sound reproducer especially adapted for use in gramo- Y phones.

Another object of my invention is to provide an improved diaphragm for a sound reproducer.

Still another object of my invention is to provide a sound reproducer with its diaphragm so formed as to reproduce sounds from a record with a superior proportioning and quality of the various component tones.

All these objects will be made apparent in connection rwith the following specification and claims taken with the accompanying drawings in which I have illustrated one specific embodiment of my invention.

It will be understood that the invention itself is defined in the appended claims.

As is well known to those skilled in the art, the sound waves thrown off by the diaphragm of a sound reproducer do not ordinarily combine the tone giving components inthe proper proportion as they occurred initially in the sound from which the record was derived. To this defect is due the unnaturalness of the sounds coming from such a sound reproducer. I have determined, as the result of much study and experiment, that by certain modifications of the diaphragm which I will describe, I can cause it to reinforce or accentuate the necessary overtones so as to bring out the full richness and peculiar tone color of the various instruments and voices originally employed inf making the record. Instead of making the The sound reproducer comprises a chamber wall, with a central conduit 12 for the escape of theJ sound waves generated within the chamber. Opposite to the chamber wall 11 the chamber is bounded by the specially formed diaphragm 15 whose peripheral edge is clamped between the rubber rings 14 and 16, the ring 14 lying in the annular groove 13 and the parts being clamped in place by the annular plate 17, secured by the screws 18. Around the center of the diaphragm 15 is an annular bead 19 within which is secured the upper end of the lever 20. This lever 20 vis rigidly connected with the block 21 pivoted at 22, and the block 21 carries the needle 28 secured by the set screw 24.

The diaphragm 15 has its central portion lying substantially in a plane except for the heretofore mentioned bead 19. Surrounding thev central plane portion of the diaphragm but stepped aside slightly so as to lie in a slightly oliset parallel plane, is the annular portion 15. Around this part 15 similarly stepped therefrom, is another annular portion 15". The number of these annular steps in the diaphragm may be varied within limits according tothe character and capacity of the apparatus and as may be determined by experiment and investigation. In Fig. 3 I have shown a diaphragm in only three slightly offset parallel planes. Such a diaphragm is intended and adapted for asomewhat smaller machine thanthe diaphragm shown in Fig. 2. In Fig. l I have shown a bead 19 in each annular step.

I have found, as a result of much investigation and experiment, that a sound reproducer provided with a diaphragml constructed on the principle herein set forth is admirably adapted for reproducing sounds with the most desirable tone quality.k The results obtained may be` varied and determined somewhat by the number of steps given to the diaphragmV and by the relative width of each step. I find that substantially the proportions shownin Fig. 2 of the draw- `imperforate from its center to the periphery and comprising a series of smooth concentions lying in progressively stepped parallel 10 tric annular sections lying in progressively planes.

stepped parallel planes. In testimony whereof, I have subscribed 2. In a sound box for sound-reproducing my name.

machines, an inteOral diaphravm of unorm thickness havtng a central ahole for the FOREST CHENEY" attachment of a stylus lever and imperforate /Vtnesses:

from its center to its periphery and compris- Gino. L. VILKINSON, ing a series of smooth concentric annular sec- MAURIGE BOLTON.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents.

Washington, D. C. 

